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1.
Stroke ; 53(9): 2887-2895, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35545940

RESUMEN

BACKGROUND: Individuals with sickle cell anemia have heightened risk of stroke and cognitive dysfunction. Given its high prevalence globally, whether sickle cell trait (SCT) is a risk factor for neurological injury has been of interest; however, data have been limited. We hypothesized that young, healthy adults with SCT would show normal cerebrovascular structure and hemodynamic function. METHODS: As a case-control study, young adults with (N=25, cases) and without SCT (N=24, controls) underwent brain magnetic resonance imaging to quantify brain volume, microstructural integrity (fractional anisotropy), silent cerebral infarcts (SCI), intracranial stenosis, and aneurysms. Pseudocontinuous arterial spin labeling and asymmetric spin echo sequences measured cerebral blood flow and oxygen extraction fraction, respectively, from which cerebral metabolic oxygen demand was calculated. Imaging metrics were compared between SCT cases and controls. SCI volume was correlated with baseline characteristics. RESULTS: Compared with controls, adults with SCT demonstrated similar normalized brain volumes (SCT 0.80 versus control 0.81, P=0.41), white matter fractional anisotropy (SCT 0.41 versus control 0.43, P=0.37), cerebral blood flow (SCT 62.04 versus control, 61.16 mL/min/100 g, P=0.67), oxygen extraction fraction (SCT 0.27 versus control 0.27, P=0.31), and cerebral metabolic oxygen demand (SCT 2.71 versus control 2.70 mL/min/100 g, P=0.96). One per cohort had an intracranial aneurysm. None had intracranial stenosis. The SCT cases and controls showed similar prevalence and volume of SCIs; however, in the subset of participants with SCIs, the SCT cases had greater SCI volume versus controls (0.29 versus 0.07 mL, P=0.008). Of baseline characteristics, creatinine was mildly elevated in the SCT cohort (0.9 versus 0.8 mg/dL, P=0.053) and correlated with SCI volume (ρ=0.49, P=0.032). In the SCT cohort, SCI distribution was similar to that of young adults with sickle cell anemia. CONCLUSIONS: Adults with SCT showed normal cerebrovascular structure and hemodynamic function. These findings suggest that healthy individuals with SCT are unlikely to be at increased risk for early or accelerated ischemic brain injury.


Asunto(s)
Anemia de Células Falciformes , Rasgo Drepanocítico , Sustancia Blanca , Anemia de Células Falciformes/diagnóstico por imagen , Anemia de Células Falciformes/epidemiología , Estudios de Casos y Controles , Infarto Cerebral/diagnóstico por imagen , Infarto Cerebral/epidemiología , Infarto Cerebral/etiología , Constricción Patológica/complicaciones , Humanos , Imagen por Resonancia Magnética/métodos , Oxígeno/metabolismo , Rasgo Drepanocítico/diagnóstico por imagen , Estrés Fisiológico , Adulto Joven
2.
J Comput Assist Tomogr ; 46(5): 770-774, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35617649

RESUMEN

BACKGROUND AND PURPOSE: Intracranial hemorrhage (ICH) is a common finding in patients presenting to the emergency department with acute neurological symptoms. Noncontrast head computed tomography (NCCT) is the primary modality for assessment and detection of ICH in the acute setting. RAPID ICH software aims to automatically detect ICH on NCCT and was previously shown to have high accuracy when applied to a curated test data set. Here, we measured the test performance characteristics of RAPID ICH software in detecting ICH on NCCT performed in patients undergoing emergency stroke evaluation at a tertiary academic comprehensive stroke center. MATERIALS AND METHODS: This retrospective study assessed consecutive patients over a 6-month period who presented with acute neurological symptoms suspicious for stroke and underwent NCCT with RAPID ICH postprocessing. RAPID ICH detection was compared with the interpretation of a reference standard comprising a board-certified or board-eligible neuroradiologist, or in cases of discrepancy, adjudicated by a consensus panel of 3 neuroradiologists. Accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of RAPID ICH for ICH detection were determined. RESULTS: Three hundred seven NCCT scans were included in the study. RAPID ICH correctly identified 34 of 37 cases with ICH and 228 of 270 without ICH. RAPID ICH had a sensitivity of 91.9% (78.1%-98.3%), specificity of 84.4% (79.6%-88.6%), NPV of 98.7% (96.3%-99.6%), PPV of 44.7% (37.6%-52.1%), and overall accuracy of 85.3% (80.9%-89.1%). CONCLUSIONS: In a real-world scenario, RAPID ICH software demonstrated high NPV but low PPV for the presence of ICH when evaluating possible stroke patients.


Asunto(s)
Hemorragias Intracraneales , Accidente Cerebrovascular , Humanos , Hemorragias Intracraneales/diagnóstico por imagen , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Accidente Cerebrovascular/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos
3.
Blood ; 131(9): 1012-1021, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29255068

RESUMEN

Blood transfusions are the mainstay of stroke prevention in pediatric sickle cell anemia (SCA), but the physiology conferring this benefit is unclear. Cerebral blood flow (CBF) and oxygen extraction fraction (OEF) are elevated in SCA, likely compensating for reduced arterial oxygen content (CaO2). We hypothesized that exchange transfusions would decrease CBF and OEF by increasing CaO2, thereby relieving cerebral oxygen metabolic stress. Twenty-one children with SCA receiving chronic transfusion therapy (CTT) underwent magnetic resonance imaging before and after exchange transfusions. Arterial spin labeling and asymmetric spin echo sequences measured CBF and OEF, respectively, which were compared pre- and posttransfusion. Volumes of tissue with OEF above successive thresholds (36%, 38%, and 40%), as a metric of regional metabolic stress, were compared pre- and posttransfusion. Transfusions increased hemoglobin (Hb; from 9.1 to 10.3 g/dL; P < .001) and decreased Hb S (from 39.7% to 24.3%; P < .001). Transfusions reduced CBF (from 88 to 82.4 mL/100 g per minute; P = .004) and OEF (from 34.4% to 31.2%; P < .001). At all thresholds, transfusions reduced the volume of peak OEF found in the deep white matter, a location at high infarct risk in SCA (P < .001). Reduction of elevated CBF and OEF, both globally and regionally, suggests that CTT mitigates infarct risk in pediatric SCA by relieving cerebral metabolic stress at patient- and tissue-specific levels.


Asunto(s)
Anemia de Células Falciformes , Circulación Cerebrovascular , Transfusión de Eritrocitos , Angiografía por Resonancia Magnética , Oxígeno/sangre , Adolescente , Anemia de Células Falciformes/sangre , Anemia de Células Falciformes/diagnóstico por imagen , Anemia de Células Falciformes/fisiopatología , Anemia de Células Falciformes/terapia , Velocidad del Flujo Sanguíneo , Niño , Preescolar , Femenino , Humanos , Masculino
5.
Stroke ; 47(1): 99-105, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26585394

RESUMEN

BACKGROUND AND PURPOSE: We aimed to examine perfusion changes between 3 and 6 and 6 and 24 hours after stroke onset and their impact on tissue outcome. METHODS: Acute ischemic stroke patients underwent perfusion magnetic resonance imaging at 3, 6, and 24 hours after stroke onset and follow-up fluid-attenuated inversion recovery at 1 month to assess tissue fate. Mean transit time prolongation maps (MTTp=MTT-[median MTT of contralateral hemisphere]) were obtained at 3 (MTTp3 h), 6 (MTTp6 h), and 24 hours (MTTp24 h). Perfusion changes between 3 and 6 hours (ΔMTTp3_6) and 6 and 24 hours (ΔMTTp6_24) were calculated. A 2-step analysis was performed to evaluate the impact of ΔMTTp3_6 and ΔMTTp6_24 on tissue fate. First, a voxel-based multivariable logistic regression was performed for each individual patient with MTTp3 h, ΔMTTp3_6, and ΔMTT6_24 as independent variables and tissue fate as outcome. Second, Wilcoxon signed-rank tests on logistic regression coefficients were performed across patients to evaluate whether ΔMTTp3_6 and ΔMTT6_24 had significant impact on tissue fate for varying severities of baseline perfusion. RESULTS: Perfusion change was common during both time periods: 85% and 81% of patients had perfusion improvement during 3- to 6- and 6- and 24-hour time intervals, respectively. ΔMTT3_6 significantly influenced 1-month infarct probability across a wide range of baseline perfusion (MTTp 0-15 s). ΔMTT6_24 also impacted 1-month infarct probability, but its influence was restricted to tissue with milder baseline ischemia (MTTp 0-10 s). CONCLUSIONS: Brain tissue with mild to moderate ischemia can be salvaged by reperfusion even after 6 hours. Such tissue could be targeted for intervention beyond current treatment windows.


Asunto(s)
Isquemia Encefálica/diagnóstico , Isquemia Encefálica/cirugía , Reperfusión/tendencias , Accidente Cerebrovascular/diagnóstico , Accidente Cerebrovascular/cirugía , Anciano , Infarto Cerebral/diagnóstico , Infarto Cerebral/cirugía , Humanos , Angiografía por Resonancia Magnética/tendencias , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo
6.
Stroke ; 47(4): 1012-7, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26892282

RESUMEN

BACKGROUND AND PURPOSE: Stroke mimics (SM) challenge the initial assessment of patients presenting with possible acute ischemic stroke (AIS). When SM is considered likely, intravenous tissue-type plasminogen activator (tPA) may be withheld, risking an opportunity to treat AIS. Although computed tomography is routinely used for tPA decision making, magnetic resonance imaging (MRI) may diagnose AIS when SM is favored but not certain. We hypothesized that a hyperacute MRI (hMRI) protocol would identify tPA-eligible AIS patients among those initially favored to have SM. METHODS: A streamlined hMRI protocol was designed based on barriers to rapid patient transport, MRI acquisition, and post-MRI tPA delivery. Neurologists were trained to order hMRI when SM was favored and tPA was being withheld. The use of hMRI for tPA decision making, door-to-needle times, and outcomes were compared before hMRI implementation (pre-hMRI: August 1, 2011 to July 31, 2013) and after (post-hMRI, August 1, 2013, to January 15, 2015). RESULTS: Post hMRI, 57 patients with suspected SM underwent hMRI (median MRI-order-to-start time, 29 minutes), of whom, 11 (19%) were diagnosed with AIS and 7 (12%) received tPA. Pre-hMRI, no tPA-treated patients were screened with hMRI. Post hMRI, 7 of 106 (6.6%) tPA-treated patients underwent hMRI to aid in decision making because of suspected SM (0% versus 6.6%; P=0.001). To ensure standard care was maintained after implementing the hMRI protocol, pre- versus post-hMRI tPA-treated cohorts were compared and did not differ: door-to-needle time (39 versus 37 minutes; P=0.63), symptomatic hemorrhage rate (4.5% versus 1.9%; P=0.32), and favorable discharge location (85% versus 89%; P=0.37). CONCLUSIONS: A streamlined hMRI protocol permitted tPA administration to a small, but significant, subset of AIS patients initially considered to have SM.


Asunto(s)
Isquemia Encefálica/patología , Fibrinolíticos/uso terapéutico , Imagen por Resonancia Magnética/métodos , Accidente Cerebrovascular/patología , Activador de Tejido Plasminógeno/uso terapéutico , Administración Intravenosa , Adulto , Anciano , Isquemia Encefálica/tratamiento farmacológico , Toma de Decisiones Clínicas , Diagnóstico Diferencial , Femenino , Humanos , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/tratamiento farmacológico , Resultado del Tratamiento
7.
Stroke ; 46(4): 982-8, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25721017

RESUMEN

BACKGROUND AND PURPOSE: Penumbral biomarkers promise to individualize treatment windows in acute ischemic stroke. We used a novel magnetic resonance imaging approach that measures oxygen metabolic index (OMI), a parameter closely related to positron emission tomography-derived cerebral metabolic rate of oxygen utilization (CMRO2), to derive a pair of ischemic thresholds: (1) an irreversible-injury threshold that differentiates ischemic core from penumbra and (2) a reversible-injury threshold that differentiates penumbra from tissue not-at-risk for infarction. METHODS: Forty patients with acute ischemic stroke underwent magnetic resonance imaging at 3 time points after stroke onset: <4.5 hours (for OMI threshold derivation), 6 hours (to determine reperfusion status), and 1 month (for infarct probability determination). A dynamic susceptibility contrast method measured cerebral blood flow, and an asymmetrical spin echo sequence measured oxygen extraction fraction, to derive OMI (OMI=cerebral blood flow×oxygen extraction fraction). Putative ischemic threshold pairs were iteratively tested using a computation-intensive method to derive infarct probabilities in 3 tissue groups defined by the thresholds (core, penumbra, and not-at-risk tissue). An optimal threshold pair was chosen based on its ability to predict infarction in the core, reperfusion-dependent survival in the penumbra, and survival in not-at-risk tissue. The predictive abilities of the thresholds were then tested within the same cohort using a 10-fold cross-validation method. RESULTS: The optimal OMI ischemic thresholds were found to be 0.28 and 0.42 of normal values in the contralateral hemisphere. Using the 10-fold cross-validation method, median infarct probabilities were 90.6% for core, 89.7% for nonreperfused penumbra, 9.95% for reperfused penumbra, and 6.28% for not-at-risk tissue. CONCLUSIONS: OMI thresholds, derived using voxel-based, reperfusion-dependent infarct probabilities, delineated the ischemic penumbra with high predictive ability. These thresholds will require confirmation in an independent patient sample.


Asunto(s)
Isquemia Encefálica/metabolismo , Circulación Cerebrovascular/fisiología , Imagen por Resonancia Magnética/métodos , Oxígeno/metabolismo , Accidente Cerebrovascular/metabolismo , Anciano , Biomarcadores/metabolismo , Isquemia Encefálica/diagnóstico , Infarto Cerebral/diagnóstico , Infarto Cerebral/metabolismo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Reproducibilidad de los Resultados , Accidente Cerebrovascular/diagnóstico
8.
Epileptic Disord ; 24(6): 1102-1109, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36193019

RESUMEN

Non-ketotic hyperglycemia (NKH) is associated with a spectrum of symptoms and radiographic findings due to poorly-controlled diabetes mellitus. These lesions, which predominantly affect the parieto-occipital cortex, are commonly missed by neurologists and neuroradiologists due to their subtle hypointense appearance on T2-based imaging. We report four atypical cases of this syndrome to highlight its subtle, protean presentation in order to aid timely diagnosis. Based on our institutional case series, we describe four cases of NKH with atypical presentation and lesion burden affecting the anterior cortex. We review the clinical presentations, laboratory abnormalities, neuroimaging, and corresponding electroencephalography. Four patients with atypical NKH were characterized in our series. Presenting symptoms ranged from rhythmic hand-tapping to generalized tonic-clonic status epilepticus. Laboratory values were notable for marked hyperglycemia (range: 447 - 627 mg/dL), mild pseudo-hyponatremia (range: 127 - 136 mmol/L), and elevated hemoglobin A1C levels (range: 10.9 - 16.1%). All patients were found to have the classically described pattern of T2-based hypointensity; three with atypical distributions involving the "anterior" cortex. These lesions corresponded to the electrographic nidus of seizure burden. During follow-up, both seizures and T2-based hypointensity resolved within weeks of serum glucose normalization. Our series of four NKH patients with atypical findings of T2-based signal abnormalities expands the clinico-radiographic phenotype revealing a more protean distribution than previously described. Knowledge of these atypical imaging features will aid both the neurologist and radiologist in timely diagnosis and care of these patients.


Asunto(s)
Epilepsia , Hiperglucemia , Electroencefalografía , Epilepsia/complicaciones , Glucosa , Hemoglobina Glucada , Humanos , Hiperglucemia/complicaciones , Cetosas , Fenotipo , Convulsiones/diagnóstico
9.
Stroke ; 42(5): 1307-13, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21454815

RESUMEN

BACKGROUND AND PURPOSE: Statin pretreatment has been associated with improved outcomes in patients with ischemic stroke. Although several mechanisms have been examined in animal models, few have been examined in patients. We hypothesized that patients using statins before stroke onset may have greater reperfusion than patients not using statins. METHODS: Acute ischemic stroke patients underwent 2 MR scans: within 4.5 (tp1) and at 6 hours (tp2) after stroke onset. Regions of reperfusion were defined by prolonged mean transit time (MTT) at tp1, which normalized at tp2. Four MTT thresholds were assessed to ensure that results were not spuriously based on an arbitrary threshold. Baseline characteristics, relative reperfusion, and change in NIHSS between tp1 and 1-month follow-up (ΔNIHSS) were compared between patients who were using statins at stroke onset and those who were not. RESULTS: Thirty-one stroke patients were prospectively enrolled; 12 were using statins and 19 were not. Baseline characteristics did not differ between the 2 groups except the statin group had greater coronary artery disease (P=0.03). Patients using statins showed significantly greater reperfusion compared to untreated patients across all MTT thresholds. For MTT of 4 seconds, median relative reperfusion was 50% (interquartile range, 30%-56%) in the preexisting statin group versus 13% (interquartile range, 5%-36%) in the untreated group (P=0.014). The statin group had greater ΔNIHSS (8.8±4.0 points) compared to the untreated group (4.4±5.7 points; P=0.028). CONCLUSIONS: Statin use before ischemic stroke onset was associated with greater early reperfusion and NIHSS improvement. Further studies in larger populations are required to confirm our preliminary findings.


Asunto(s)
Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Reperfusión , Accidente Cerebrovascular/fisiopatología , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Prospectivos , Estudios Retrospectivos , Accidente Cerebrovascular/diagnóstico , Factores de Tiempo , Resultado del Tratamiento
10.
Neurology ; 97(9): e902-e912, 2021 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-34172536

RESUMEN

OBJECTIVE: To determine the patient- and tissue-based relationships between cerebral hemodynamic and oxygen metabolic stress, microstructural injury, and infarct location in adults with sickle cell disease (SCD). METHODS: Control participants and patients with SCD underwent brain MRI to quantify cerebral blood flow (CBF), oxygen extraction fraction (OEF), mean diffusivity (MD), and fractional anisotropy (FA) within normal-appearing white matter (NAWM) and infarcts on fluid-attenuated inversion recovery. Multivariable linear regression examined the patient- and voxel-based associations between hemodynamic and metabolic stress (defined as elevated CBF and OEF, respectively), white matter microstructure, and infarct location. RESULTS: Of 83 control participants and patients with SCD, adults with SCD demonstrated increased CBF (50.9 vs 38.8 mL/min/100 g, p < 0.001), increased OEF (0.35 vs 0.25, p < 0.001), increased MD (0.76 vs 0.72 × 10-3 mm2s-1, p = 0.005), and decreased FA (0.40 vs 0.42, p = 0.021) within NAWM compared to controls. In multivariable analysis, increased OEF (ß = 0.19, p = 0.035), but not CBF (ß = 0.00, p = 0.340), independently predicted increased MD in the SCD cohort; neither were predictors in controls. On voxel-wise regression, the SCD cohort demonstrated widespread OEF elevation, encompassing deep white matter regions of elevated MD and reduced FA, which spatially extended beyond high-density infarct locations from the SCD cohort. CONCLUSION: Elevated OEF, a putative index of cerebral oxygen metabolic stress, may provide a metric of ischemic vulnerability that could enable individualization of therapeutic strategies in SCD. The patient- and tissue-based relationships between elevated OEF, elevated MD, and cerebral infarcts suggest that oxygen metabolic stress may underlie microstructural injury prior to the development of cerebral infarcts in SCD.


Asunto(s)
Anemia de Células Falciformes , Sustancia Blanca , Adulto , Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/diagnóstico por imagen , Infarto Cerebral , Circulación Cerebrovascular , Humanos , Imagen por Resonancia Magnética , Oxígeno , Consumo de Oxígeno , Estrés Fisiológico , Sustancia Blanca/diagnóstico por imagen
12.
Clin Neurol Neurosurg ; 172: 27-30, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29960103

RESUMEN

OBJECTIVE: Computed tomographic angiography (CTA) is increasingly utilized to evaluate for traumatic cerebrovascular injury (TCVI). The purpose of this study was to determine the yield, management effect, and risk of stroke or poor outcome of a positive CTA in a large cohort of trauma patients. PATIENTS AND METHODS: A retrospective analysis was performed on 1290 consecutive trauma patients that underwent head and/or neck CTA at our level I trauma center from 2006 to 2015. Clinical variables assessed include mechanism of injury, neurological status, CTA findings, subsequent imaging results, patient management, and clinical outcomes. RESULTS: Among 1290 patients who underwent CTA, 200 (15.5%) were positive for TCVI, higher in blunt than penetrating trauma patients. In a generalized linear model, factors that increased likelihood of positive CTA included multiple cervical fractures, fractures with foraminal involvement, gunshot injury, Glasgow Coma Scale ≤ 13, and focal neurological deficit. Excluding cases with these factors lowered the positive rate to 4.3%. Of the 200 CTA-positives, 99 were treated for TCVI and 9 (4.5%) developed a subsequent stroke as compared to 5 (0.5%) in CTA-negative patients (odds ratio 10.2, Fisher exact test, p < 0.001). Risk of death or nursing facility discharge location was also higher in CTA-positive patients, correcting for age and presenting GCS (p < 0.01). CONCLUSION: CTA had a modest yield in identifying TCVI in this cohort. When positive, CTA influenced management and predicted an increased risk of subsequent stroke and poor outcome.


Asunto(s)
Angiografía Cerebral , Traumatismos Cerebrovasculares/diagnóstico por imagen , Accidente Cerebrovascular/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Angiografía de Substracción Digital/métodos , Angiografía Cerebral/métodos , Femenino , Escala de Coma de Glasgow , Humanos , Masculino , Persona de Mediana Edad , Traumatismos del Cuello/complicaciones , Factores de Riesgo , Accidente Cerebrovascular/etiología , Centros Traumatológicos , Heridas no Penetrantes/complicaciones
13.
Neurology ; 90(13): e1134-e1142, 2018 03 27.
Artículo en Inglés | MEDLINE | ID: mdl-29500287

RESUMEN

OBJECTIVE: To determine mechanisms underlying regional vulnerability to infarction in sickle cell disease (SCD) by measuring voxel-wise cerebral blood flow (CBF), oxygen extraction fraction (OEF), and cerebral metabolic rate of oxygen utilization (CMRO2) in children with SCD. METHODS: Participants underwent brain MRIs to measure voxel-based CBF, OEF, and CMRO2. An infarct heat map was created from an independent pediatric SCD cohort with silent infarcts and compared to prospectively obtained OEF maps. RESULTS: Fifty-six participants, 36 children with SCD and 20 controls, completed the study evaluation. Whole-brain CBF (99.2 vs 66.3 mL/100 g/min, p < 0.001), OEF (42.7% vs 28.8%, p < 0.001), and CMRO2 (3.7 vs 2.5 mL/100 g/min, p < 0.001) were higher in the SCD cohort compared to controls. A region of peak OEF was identified in the deep white matter in the SCD cohort, delineated by a ratio map of average SCD to control OEF voxels. CMRO2 in this region, which encompassed the CBF nadir, was low relative to all white matter (p < 0.001). Furthermore, this peak OEF region colocalized with regions of greatest infarct density derived from an independent SCD cohort. CONCLUSIONS: Elevated OEF in the deep white matter identifies a signature of metabolically stressed brain tissue at increased stroke risk in pediatric patients with SCD. We propose that border zone physiology, exacerbated by chronic anemic hypoxia, explains the high risk in this region.


Asunto(s)
Anemia de Células Falciformes/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Interpretación de Imagen Asistida por Computador , Imagen por Resonancia Magnética , Oxígeno/metabolismo , Accidente Cerebrovascular/diagnóstico por imagen , Adolescente , Anemia de Células Falciformes/metabolismo , Anemia de Células Falciformes/terapia , Encéfalo/metabolismo , Circulación Cerebrovascular , Niño , Preescolar , Estudios de Cohortes , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Consumo de Oxígeno , Accidente Cerebrovascular/metabolismo , Adulto Joven
14.
Stroke ; 38(12): 3289-91, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17962594

RESUMEN

BACKGROUND AND PURPOSE: Stroke-prone spontaneous hypertensive rats (SHRsp) fed a high-salt diet develop malignant hypertension, blood-brain barrier breakdown, and spontaneous intracerebral hemorrhage (ICH). The precise spatial and temporal relationship between these events has not been well-delineated. METHODS: Ten SHRsp male rats, fed a high-salt diet, were imaged weekly using MRI, starting at 12 weeks of age. T1-weighted (with and without Gd), T2-weighted, and T2* sequences were acquired. Permeability maps were calculated. RESULTS: Seven SHRsp rats had spontaneous ICH develop before death. Five of the 7 rats had focally increased vascular permeability at the site of the ICH; 3 of these rats had vascular permeability 1 to 2 weeks before spontaneous ICH. CONCLUSIONS: Salt-loaded SHRsp rats have increased vascular permeability up to 2 weeks before ICH, predicting hemorrhage both in space and time. These results suggest that hypertensive ICH is preceded by focal vasculopathy detectable by Gd leak.


Asunto(s)
Hemorragia Cerebral/diagnóstico , Accidente Cerebrovascular/patología , Animales , Presión Sanguínea , Barrera Hematoencefálica , Permeabilidad Capilar , Hemorragia Cerebral/patología , Hipertensión , Imagen por Resonancia Magnética/métodos , Masculino , Permeabilidad , Ratas , Ratas Endogámicas SHR , Ratas Endogámicas WKY , Factores de Tiempo
15.
Clin Neurol Neurosurg ; 109(8): 713-5, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17583421

RESUMEN

Marchiafava-Bignami disease (MBD) is historically reported in middle-aged alcoholic men. We describe the presentation, course and radiological findings of a young non-alcoholic woman who developed encephalopathy and MRI findings consistent with MBD postoperatively. She returned to baseline after vitamin supplementation. We believe it is important to diagnose MBD because it is a potentially reversible encephalopathy.


Asunto(s)
Colecistectomía/efectos adversos , Trastornos de la Conciencia/etiología , Epilepsia/etiología , Enfermedad de Marchiafava-Bignami/diagnóstico , Adulto , Femenino , Humanos , Enfermedad de Marchiafava-Bignami/complicaciones , Enfermedad de Marchiafava-Bignami/terapia
16.
Pediatr Neurol ; 69: 49-57, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28159432

RESUMEN

BACKGROUND: Large-vessel vasculopathy (LVV) increases stroke risk in pediatric sickle cell disease beyond the baseline elevated stroke risk in this vulnerable population. The mechanisms underlying this added risk and its unique impact on the developing brain are not established. METHODS: We analyzed magnetic resonance imaging and angiography scans of 66 children with sickle cell disease and infarcts by infarct density heatmaps and Jacobian determinants, a metric utilized to delineate focal volume change, to investigate if infarct location, volume, frequency, and cerebral atrophy differed among hemispheres with and without LVV. RESULTS: Infarct density heatmaps demonstrated infarct "hot spots" within the deep white matter internal border zone region in both LVV and non-LVV hemispheres, but with greater infarct density and larger infarct volumes in LVV hemispheres (2.2 mL versus 0.25 mL, P < 0.001). Additional scattered cortical infarcts in the internal carotid artery territory occurred in LVV hemispheres, but were rare in non-LVV hemispheres. Jacobian determinants revealed greater atrophy in gray and white matter of the parietal lobes of LVV compared with non-LVV hemispheres. CONCLUSION: Large-vessel vasculopathy in sickle cell disease appears to increase ischemic vulnerability in the borderzone region, as demonstrated by the increased frequency and extent of infarction within deep white matter, and increased risk of focal atrophy. Scattered infarctions across the LVV-affected hemispheres suggest additional stroke etiologies of vasculopathy (i.e., thromboembolism) in addition to chronic hypoxia-ischemia.


Asunto(s)
Anemia de Células Falciformes/complicaciones , Anemia de Células Falciformes/diagnóstico por imagen , Angiografía Cerebral , Infarto Cerebral/complicaciones , Infarto Cerebral/diagnóstico por imagen , Imagen por Resonancia Magnética , Adolescente , Atrofia/complicaciones , Atrofia/diagnóstico por imagen , Encéfalo/diagnóstico por imagen , Niño , Preescolar , Estudios Transversales , Femenino , Humanos , Masculino , Estudios Retrospectivos , Adulto Joven
17.
Global Spine J ; 6(4): 370-4, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27190740

RESUMEN

Study Design Retrospective cohort. Objective To clarify the sensitivity of C3-C2 spinolaminar line test as a screening tool for the stenosis of C1 space available for the cord (SAC). Methods Spine clinic records from April 2005 to August 2011 were reviewed. The C1 SAC was measured on lateral radiographs, and the relative positions between a C1 posterior arch and the C3-C2 spinolaminar line were examined and considered "positive" when the C1 ring lay ventral to the line. Computed tomography (CT) scans and magnetic resonance imaging (MRI) were utilized to measure precise diameters of C1 and C2 SAC and to check the existence of spinal cord compression. Results Four hundred eighty-seven patients were included in this study. There were 246 men and 241 women, with an average age of 53 years (range: 18 to 86). The mean SAC at C1 on radiographs was 21.2 mm (range: 13.5 to 28.2). Twenty-one patients (4.3%) were positive for the spinolaminar line test; all of these patients had C1 SAC of 19.4 mm or less. Eight patients (1.6%) had C1 SAC smaller than C2 on CT examination; all of these patients had a positive spinolaminar test, with high sensitivity (100%) and specificity (97%). MRI analysis revealed that two of the eight patients with a smaller C1 SAC had spinal cord compression at the C1 level. Conclusion Although spinal cord compression at the level of atlas without instability is a rare condition, the spinolaminar line can be used as a screening of C1 stenosis.

18.
Neurology ; 87(3): 270-6, 2016 07 19.
Artículo en Inglés | MEDLINE | ID: mdl-27316244

RESUMEN

OBJECTIVE: To describe the neurologic and neuroimaging manifestations associated with Cantú syndrome. METHODS: We evaluated 10 patients with genetically confirmed Cantú syndrome. All adult patients, and pediatric patients who were able to cooperate and complete the studies, underwent neuroimaging, including vascular imaging. A salient neurologic history and examination was obtained for all patients. RESULTS: We observed diffusely dilated and tortuous cerebral blood vessels in all patients who underwent vascular imaging. White matter changes were observed in all patients who completed an MRI brain study. Two patients had a persistent trigeminal artery. One patient had an occluded right middle cerebral artery. One patient had transient white matter changes suggestive of posterior reversible encephalopathic syndrome. Four patients had migraines with one patient having complicated migraines. Seizures were seen in early life but infrequent. The majority of patients had mild developmental delays and one patient had a diagnosis of autism. CONCLUSIONS: Cantú syndrome is associated with various neurologic manifestations, particularly cerebrovascular findings including dilated and tortuous cerebral vessels, white matter changes, and persistent fetal circulation. Involvement of the KATP SUR2/Kir6.1 subtype potentially plays an important role in the neurologic manifestations of Cantú syndrome.


Asunto(s)
Encéfalo/irrigación sanguínea , Cardiomegalia/diagnóstico por imagen , Cardiomegalia/diagnóstico , Hipertricosis/diagnóstico por imagen , Hipertricosis/diagnóstico , Osteocondrodisplasias/diagnóstico por imagen , Osteocondrodisplasias/diagnóstico , Adolescente , Adulto , Encéfalo/patología , Cardiomegalia/patología , Niño , Preescolar , Femenino , Humanos , Hipertricosis/patología , Lactante , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Neuroimagen , Osteocondrodisplasias/patología , Tomografía Computarizada por Rayos X , Sustancia Blanca/diagnóstico por imagen , Sustancia Blanca/patología , Adulto Joven
19.
Stroke ; 34(1): 64-70, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12511752

RESUMEN

BACKGROUND AND PURPOSE: Diffusion-weighted imaging (DWI) has been established as a marker of acute ischemic brain injury. We sought to determine the relationship between cerebral blood flow (CBF) and apparent diffusion coefficient (ADC) and to explore whether the elapsed time between MRI acquisition and symptom onset alters this relation in acute stroke patients. METHODS: Sixteen acute stroke patients were studied with DWI and perfusion-weighted imaging, from which ADC and CBF were calculated. ADC values were normalized (nADC) to the contralateral, nonischemic hemisphere and then correlated pixel by pixel with CBF within a region of interest defined by abnormal transit time. To explore potential temporal effects on the relationship between CBF and nADC, patients were divided into 2 groups based on the duration between symptom onset and MR imaging for data analysis: group A, 2 to 4 hours (n=8), and group B, 4.5 to 6.5 hours (n=8). RESULTS: nADC was plotted against CBF for each pixel in all 16 subjects, and a composite relationship was derived. After a gradual decline, an abrupt drop in nADC occurred below a CBF threshold value of 21 mL x min(-1) x 100 g(-1). When subjects were divided into early and late imaging groups, the group of patients imaged earlier (group A) had a lower threshold (15 mL x min(-1) x 100 g(-1)) than the group imaged later (group B, 24 mL x min(-1) x 100 g(-1)). CONCLUSIONS: Our results demonstrate that a relationship between nADC and CBF exists in the ischemic brain and that ADC values alone may provide useful information in predicting perfusion status. However, this relationship may change with elapsing time between stroke onset and imaging.


Asunto(s)
Circulación Cerebrovascular , Imagen de Difusión por Resonancia Magnética/métodos , Angiografía por Resonancia Magnética/métodos , Accidente Cerebrovascular/diagnóstico , Adulto , Anciano , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatología , Difusión , Femenino , Humanos , Cinética , Masculino , Persona de Mediana Edad , Accidente Cerebrovascular/fisiopatología , Factores de Tiempo
20.
AJNR Am J Neuroradiol ; 24(4): 674-9, 2003 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12695202

RESUMEN

BACKGROUND AND PURPOSE: Early parenchymal gadolinium enhancement on T1-weighted MR images is predictive of hemorrhagic transformation (HT) in rodent focal ischemia models, but its value in humans is unknown. We sought to investigate gadolinium enhancement in acute ischemic stroke patients to determine their association with subsequent HT. METHODS: We retrospectively examined 22 patients with ischemic stroke who underwent MR imaging within 4.9 hours (+/-1.4) of symptom onset. Patients receiving intravenous tissue plasminogen activator (tPA) (n = 6) were included. Twenty-one patients underwent repeat MR studies at 48 hours, 13 underwent additional MR imaging at 1 week, and one underwent follow-up head CT at 24 hours. Initial images were analyzed for enhancement patterns (vascular, meningeal, parenchymal). Follow-up T2- and T2*-weighted images were evaluated for hemorrhage. RESULTS: In all patients, initial MR images showed vascular enhancement in the vascular territory of the stroke lesion: 19 with vascular enhancement alone and three with vascular and parenchymal enhancement. All three patients with both enhancement patterns had HT: two large and symptomatic, and one asymptomatic (petechial hemorrhage). They received tPA before MR imaging. None of the patients without early parenchymal enhancement developed symptomatic hemorrhage. Six (32%) patients with vascular enhancement alone had petechial hemorrhage at follow-up imaging. In this limited sample, initial mean volumes on diffusion-weighted images, National Institute of Health Stroke Scale scores, and intervals from stroke onset to imaging did not differ between patients with vascular and parenchymal enhancement versus those with vascular enhancement alone. CONCLUSION: Early parenchymal enhancement of stroke lesions may be a good predictor of subsequent symptomatic HT may help identify patients at risk, especially after thrombolytic therapy.


Asunto(s)
Hemorragia Cerebral/diagnóstico , Infarto Cerebral/diagnóstico , Imagen de Difusión por Resonancia Magnética/métodos , Imagen Eco-Planar/métodos , Aumento de la Imagen/métodos , Procesamiento de Imagen Asistido por Computador/métodos , Anciano , Anciano de 80 o más Años , Encéfalo/patología , Arterias Cerebrales/patología , Hemorragia Cerebral/inducido químicamente , Infarto Cerebral/tratamiento farmacológico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Examen Neurológico , Fármacos Neuroprotectores/administración & dosificación , Pronóstico , Ensayos Clínicos Controlados Aleatorios como Asunto , Valores de Referencia , Estudios Retrospectivos , Factores de Riesgo , Sensibilidad y Especificidad , Terapia Trombolítica , Activador de Tejido Plasminógeno/administración & dosificación , Activador de Tejido Plasminógeno/efectos adversos , Tomografía Computarizada por Rayos X
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